1. Field of the Invention
The present invention relates to a communication server connected to two or more terminals participating in a videoconference to manage communications between the terminals, and relates to a communication system including the communication server, and a communication method performed by the communication server.
2. Description of the Related Art
A videoconference system to conduct videoconferences between communication terminals at remote places via a network, such as the Internet, is becoming increasingly popular. In this videoconference system, a videoconference is conducted by exchanging video and audio data between the communication terminals.
A communication terminal in a conference room in which one of the attendants of the videoconference is present collects information including an image of the conference room and voice of the attendants, converts the collected information into digital image and voice data, and transmits the resulting image and voice data to a communication terminal of the other party in the videoconference system. In the other party's terminal, an image is displayed on a display of the other party's terminal and voice is output by a speaker of the other party's terminal. In the videoconference system according to the related art, a videoconference in appropriate conditions closely resembling reality may be conducted between the terminals at the remote places.
Further, in the related art, a communication terminal which transmits display data of a screen displayed on a computer to the other party's terminal via a relay device for a videoconference system, so that the screen is displayed on a display of the other party's terminal is also known.
For example, Japanese Laid-Open Patent Publication No. 2011-254453 discloses a communication terminal which transmits video data and display data of a screen shared with another communication terminal to the other communication terminal via a relay device. This communication terminal stores relay device information of the relay device to which the terminal transmits the display data, receives the display data from an external input device connected to the communication terminal, and transmits the received display data to the relay device indicated by the stored relay device information. Hence, the relay device transmits the display data to the other communication terminal, and the screen to be shared with the communication terminal is displayed on a display of the other communication terminal.